In a detailed statement, the department described how police officers urged residents in low-lying neighborhoods of the borough to leave their homes before the storm. It also told of how officers later carried out rescues while fierce winds and a major storm surge battered coastal areas.On the night of the storm and in the days following, officers saved over 1,100 people trapped in homes and elsewhere by fast-rising floodwaters on Staten Island, the statement said. “Many risked their lives to make rescues,” Paul J. Browne, the chief police spokesman, said in the statement. “There were transformers exploding and the danger of live wires in the water.”